The invention relates to a rotation displaying device, and more particularly to a device for displaying the rotating speed of an engine, for example, that of an agricultural machine such as a combine harvester by a color pattern, so that the machine operator can readily detect that the engine is rotating at its low speed, standard speed or high speed.
A rotation displaying device having a pointer moving in proportional relation to the rotating speed of an engine is commonly conventionally used as a means for indicating the rotating speed of the engine. While such a device can indicate the momentary rotating speed of the engine by the pointer, it is relatively awkward to immediately read the momentary value of the rotating speed of the engine due to the necessity for visually confirming the reading of the momentary rotating speed of the engine being indicated by the pointer on the rotation displaying device. Further, the machine operator may not readily identify that the thus read indication of the rotating speed of the engine belongs to its low speed, standard speed or high speed, and failure to make accurate judgement on the indicated speed for the engine may sometimes lead to a very dangerous situation.